WO1982001083A1

WO1982001083A1 - Computer controlled photographic printer

Info

Publication number: WO1982001083A1
Application number: PCT/US1981/001180
Authority: WO
Inventors: Corp Pako; J Pone; R Harvey
Original assignee: Corp Pako
Priority date: 1980-09-11
Filing date: 1981-09-02
Publication date: 1982-04-01
Also published as: EP0060265A1

Abstract

A photographic printer contains alterable storage (14) for storing negative classification parameters and other critical exposure control parameters in each of a plurality of setups. These parameters are alterable by the user of the printer. Nonvolatile EPROM storage (12) is also provided which stores nominal starting values for the classification parameters and the exposure control parameters. After a memory clear of the alterable storage (14), the nominal starting values from the nonvolatile storage (12) are automatically loaded into each of the setups. This permits the user to return the printer to operation very quickly after a memory clear has occurred, without having to load large amounts of data.

Description

COMPUTER CONTROLLED PHOTOGRAPHIC PRINTER BACKGROUND OF THE INVENTION 1. Field of the Invention.

The present invention relates to photographic printers. In particular, the present invention relates to computer controlled photographic printers which store classification parameters and other critical printer parameters used in controlling the operation of the photographic printer. 2. Description of the Prior Art.

Photographic printers typically produce photo¬ graphic prints from photographic film originals (generally negatives) . High intensity light is passed throuqh the negative and imaged on photosensitive prin paper.^" The photographic emulsion layers on the print paper are exposed and subsequently processed to produc a print of the scene contained in the negative.

A critical portion of a photographic printer is the exposure control-, which controls the exposure of the photosensitive emulsion layers in order to ensure that the image on the print paper is properly exposed. The exposure -control may utilize inputs from several different sources in order to determine the proper exposure. Most automatic photographic printers measure the optical characteristics of the negatives and classify the negatives based upon these measurements. In most printers, the negatives containing normal scenes are printed using exposures derived froπ a method known as "integration-to-gray". With this method, it is assumed that the colors of the scene in the negative will integrate to gray over the print area, since the scene contains approximately equal amounts of all three colors. While the integration-to-gray results in proper exposure of the majority of all prints, other types of scenes which can be automatically classified typically may not be correctly exposed by integration- to-gray. As a result, the exposure control of the photographic printer corrects or. adjusts the exposures depending upon which type of scene is contained in the negative.

In order to perform the complex negative classification and exposure control functions required in modern automatic photographic printers, computer controlled printers have become increasingly common. The various parameters and threshholds used in classifying negatives are typically stored in alterable storage, so that the user or a manufacturer' trained service personnel can alter the sensitivity of the classification process to certain types of scenes by varying the threshhold and other criteria. In addition, other critical printer parameters such as slope values, slope centers, button increments, gamma factors, and the like are often stored in alterable storage, so that the user or service personnel can tailor the operation of the printer to the specific film types, paper types, and other unique characteristics of the printer or the photofinisher's work. The classification and other printer parameters are typically stored in alterable random access memory (RAM) in the form of numerous "setups". Each setup is a set of data for use in printing a particular film/paper combination. The same parameters are stored in each setup, but may have different values due to the particular film or paper with which the setup is associated.

Although the RAM is typically provided with backup battery power so thatit is nonvolatile, it is still subject to loss of data due to a memory clear as a result of a malfunction of the printer. When a memory clear occurs, the alterable storage is cleared, and the classification parameters and other critical printer parameters stored in the setups are lost. In the past, upon resumption of operation of a computer controlled photographic printer after a memory clear, the user of the service technician must enter large amounts of data into the alterable storage. Since most computer control photographic printers provide a large number of "setups" for different film types and paper types, the parameters for each setup must be entered after a memory clear. The reloading of data into all of the various setups can be extremely time-consuming, and thus costly, sinc valuable production time of the printer is being lost.

In addition, since the data being entered often involves values which are altered only relatively infrequently by the user, there is a relatively high probability that the user will not understand the information being loaded, and thus may be more prone to enter incorrectly the values as they are reloaded.

In the past, the Pako MP3000 photographic printer has provided the automatic loading of a "scan value" after a memory clear. This value is loaded into the RAM as general data (i.e. not setup data) and is used as a threshhold for identifying landscape scenes.

The MP3000 printer, however, has in the past required all of the setup data to be re-entered after a memory clear, and has not permitted operation of the printer until this setup data has been entered. SUMMARY OF THE INVENTION The photographic printer of the present invention provides alterable storage for storing setup data in each of a plurality of setups and nonvolatile storage means for storing nominal ^"starting values for the setup data. The setup data includes classification parameters to be used in classifying film originals and other critical exposure control parameters. Film originals are classified based upon measured optical characteristics and the classification parameters stored in the setup then in use. Exposures are controlled based upon the classification of the film originals and the exposure control parameters stored in the setup. In the event of a memory clear in which the information stored in the alterable storage means is lost or cleared, the nominal starting values for the classification parameters are automatically loaded into each of the setups upon resumption of operation of the photographic printer. As a result, the photographic printer of the present invention is ready to operate in a relatively short time after resumption of operation after a memory clear. The nominal starting values for the parameters are selected so that the printer will typically operate satisfactorily for the average photofinisher without the need for alteration by the photofinisher.

BRIEF DESCRIPTION OF THE DRAWINGS The Figure is a block diagram of an electrical control system of a photographic printer utilizing the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The Figure shows an electrical block diagram of a computer controlled photographic printer utilizing a preferred embodiment of the present invention. The operation of the printer is coordinated and controlled by microcomputer 10, which in one preferred embodiment is an 8-bit microprocessor such as an Intel 8080A. Associated with microprocessor 10 are erasable programmable read only memory (EPROM 12

_C PI ^{" ~}'- ^~ and read/write random access memory (RAM) 14.

In the embodiment shown in the Figure, microprocessor 10 directly controls the exposure control functions of the printer through exposure control circuitry 16. Filter paddle drivers 18 and shutter paddle driver 20 are operated by exposure control circuitry 16 through interface circuit 22.

Microprocessor 10 also coordinates the operation of paper feed control 24 and film feed control 26 through control interface 28 and interface circuitry 30.

Microprocessor 10 receives control information entered by the operator of the photographic printer by means of function switches 32 and keyboard 34 on a control panel or console. Microprocessor 20 communicates with function switches 32 and keyboard 34 through control interface 28 and control console logic 36. In a preferred embodiment of the present invention, function switches 32 and keyboard 34 are generally of the type illustrated in a copending patent application Serial No. 109,825 by R.C. Laska and J. Pone, which was filed on January 7, 1980 and is assigned to the same assignee as the present application. Microprocessor 10 controls the display 38 through control interface 28. Display 28 displays a wide variety of information of importance to the operator. For example, during initial color balancing of the photographic printer, display 38 displays instructions of the steps to be performed by the operator. In another mode, display 38 preferably displays current information as to stored parameters in RAM 14 and automatic corrections being -αsed. During normal operation, display 38 displays setup number and name, or print exposure times, or error messages'.

-m - -i-i Microprocessor 10 controls print exposures based upon stored data contained in EPROM 12, setup data and general data stored in RAM 14, data received from control console logic 36, and sensor signals received from negative monitor 40. As shown in the

Figure, negative monitor 40 includes large area trans¬ mission density sensors 42, density sensor array 44, buffer amp 46, and analog-to-digital converter 48. Density sensor array 44 provides measurement of density at a plurality of individual locations on the negative. The signals from density sensor array 44 are produced when the negative is at a preview gate. LATD sensors provide red, green and blue LATD signals indicating the overall color content of the negative. LATD sensors 42 are located within the printer below a print gate.

Microprocessor 10 classifies negatives into various types of scenes based up'on the signals from LATD sensors 42 and density sensor array 44. In the preferred embodiment of the present invention, microprocessor 10 proceeds through a series of classi¬ fication tests until the signals from the LATD sensors 42 and density sensor array 44 meet certain stored classification parameters or criteria which are stored in setups in RAM 14 and in EPROM 12. Microprocessor 10 checks for over/under rejects, snow/beach scenes, landscape scenes, backlit scenes, vertically oriented scenes, outdoor scenes, and subject density failures. In a preferred embodiment of the present invention, RAM 14 contains setup data for each of a plurality of color balance setups used with different film and paper sizes. Each setup includes various classification parameters and exposure control parameters used by microprocessor 10 to control operation of the printer. The setup data stored in RAM 14 for each setup includes the following

OMH information: film size; the message to be displayed on display 38; red, green and blue density aim points; gamma factors; slope centers; over/under slope values; color balance factors; density and color button increments; temporary color/density corrections; undercorrection values; array calibration data for each film size; and a number of negative classificatio parameters including over and under reject levels; an override value for overriding the over/under reject if a minimum average density is present in the negative; and a vertical/backlit value which selects one of seven sets of criteria used in classification of backlit, vertically oriented and outdoor scenes. The vertical/backlit value is described in further detail in a copending patent application by R. Harvey and J. Freier entitled "Photographic Printer With Sensitivity Control For Classification of Negatives".

All of the setup information stored in RAM 14 is alterable, which is desirable since the photofinishe must be able to color balance the printer and tailor the exposure control and classification parameters used by microprocessor 10 for particular film types, paper types, and negative populations. When, however, a memory clear occurs due to a malfunction, all of the information stored in RAM 14, including the setup data, is cleared. In the present invention, nominal starting values for all of the setup data needed to reinitiate operation of the photographic printer are stored in EPROM 12, fexcept color balance factors and any calibration data) . After a memory clear, microprocessor 10 automatically loads these nominal starting values into all setups in RAM 14. In a preferred embodiment of the present invention, all of the negative classification parameters have nominal starting values which are loaded into all of the setups. - These include SNRA value, over and under

OIylFI reject levels, the override level, and the vertical/ backlit value. As a result, the operator does not have to load large amounts of negative classification parameters into each of the setups just to reinitiate operation after a memory clear. Since the negative classification parameters are often left unchanged by relatively unsophisticated photofinishers, and are varied only rather infrequently by sophisiticated photofinishers, the automatic loading of nominal starting values greatly simplifies the reinitiation of operation and reduces lost production time.

In the preferred embodiment of the present invention, gamma factors, slope centers, ever/under slope values, button increments, and undercorrection values also have nominal starting values stored in EPROM 12. These nominal starting values are also loaded into all setups by microprocessor 10 after a memory clear. With the present invention, therefore, the operator in essence only has to re-enter the color balance factors into each setup and recalibrate array 44 in order to recommence operation.

In conclusion, the improved photographic printer of the present invention provides automatic loading of nominal starting values of setup data into all setups after a memory clear. The present invention, therefore, permits the photofinisher to reinitiate operation of the printer without having to enter through a keyboard vast amounts of setup data. Lost production time, therefore, is minimized. Although the present invention has been describe with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

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Claims

WHAT IS CLAIMED IS:

1. In a photographic printer in which photographic prints are produced from photographic film originals, the improvement comprising: alterable storage means for storing, in each of a plurality of setups, setup data including classification parameters and exposure control parameters,- nonvolatile storage means for storing nominal starting values for the classification parameters and the exposure control parameters; means for measuring optical characteristics of film originals; means for selecting one of the plurality of setups; means for classifying the film originals based upon the measured optical characteristics and the classification parameters stored in the selected setup; means for controlling exposures of the film originals based upon the classification of the film originals and the exposure contro parameters stored in the selected setup; and means for automatically loading the nominal starting values into each of the plurality of setups if the alterable storage means is clear.

2. The invention of claim 1 wherein the exposure control parameters include slope values.

3. The invention of claim 1 wherein the exposure control parameters include slope center values.

4. The invention of claim 1 wherein the exposure control parameters include correction button increment values.

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5. The invention of claim 1 wherein the exposure control parameters include gamma factors.

6. The invention of claim 1 wherein the classificati parameters include parameters for identifying over and under exposed film originals.

7. The invention of claim 1 wherein the classifi¬ cation parameters include criteria for identifying snow and beach scenes.

8. The invention of claim 1 wherein the classificati parameters include a value for controlling sensitivity of the means for classifying to vertically oriented and backlit scenes.

9. In a photographic printer in which photographic prints are produced from photographic film originals, the improvement comprising: alterable storage means for storing setup data in each of a plurality of setups; nonvolatile storage means for storing nominal starting values for the setup data; means for selecting one of the plurality of setups; means for controlling photographic exposures as a function of the setup data stored in the selected setup; and means for automatically loading the nominal . starting values to each of the plurality of setups if the alterable storage means is clear.

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