JPS5994040A - Densitometer - Google Patents

Abstract

PURPOSE:To simplify the correction work of a zero value and a gamma value, by storing data for correcting the zero value and the gamma value in a memory part to correct a measured concn. value. CONSTITUTION:Data for correcting a gamma value and a zero value is stored in a memory part 7 by the correcting data treatment part 6 of a microcomputer. Light from a light source 2 is previous through an object 1 to be measured to be incident to a light receiving element 3. The output thereof is inputted to a central treatment apparatus 4 to calculate a concn. value and correction treatment due to the correction data of the memory part 7 is applied to said concn. value while the corrected value is displayed by a display apparatus 5. Therefore, correction work is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a density needle used for measuring image density, etc. of photographic film. There are two types of densitometers: a photoelectric type and an optical visual type, but the photoelectric type is now commonly used because it has high accuracy and is consistent with individual measurements.

However, even with a photoelectric type, density measurement is affected by various factors and errors are likely to occur. Therefore, it is necessary to check the densitometer to ensure accurate measurement values, such as by using a standard density step film. is necessary. Conventionally, checking the densitometer requires volume adjustment, etc. for Niha, comma, and zero value corrections, which is very complicated. In particular, zero value correction must be performed every time the power is turned on, and this complicated volume adjustment has become an indispensable task.

This invention was created in view of the above, and the main purpose of this invention is to clarify a simple densitometer that can simplify the work of checking the densitometer, such as gamma value and zero value correction. Other objects of the invention will become apparent from the following description.

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

FIG. 1 is a block diagram showing one example of the concentration needle of the present invention, in which 1 is an object to be measured such as NECA film, 2 is a light emitting element, 3 is a light receiving element, 4 is a central processing unit,
5 is a recording or display device, 6 is a correction data processing section, T
is a storage unit that can maintain its stored state even when the power is cut off. Adjustment of the light amount of the light emitting element 2 is performed by the operation section 8, and the data thereof is introduced into the central processing unit 4. The light emitted from the light-emitting element 2 and transmitted through the object to be measured 1'f, such as a negative film, is detected by the light-receiving element 3 as an output voltage proportional to the concentration of the object to be measured 1'f, and this output voltage is sent to the central processing unit. 4
electrical processing is performed on the recording or display device 5.
is input to activate this.

The above explanation is basically the same as that of a conventional photoelectric densitometer. The densitometer of the present invention differs from conventional ones in that it includes a correction data processing section 6 and a storage section T. That is, the correction data processing section 6 uses, for example, a microcomputer, inputs and calculates data such as appropriate concentration measurement values, comparative measurement values, etc., and stores correction data specific to each densitometer in the storage section 1. The measured value when measuring the concentration of a certain object to be measured 1 is processed using the correction data stored in the storage section γ, and the output based on the obtained corrected measured value is sent through the central processing unit 4. , or directly to the recording or display device 5.

As the storage unit T, for example, a non-volatile data storage device may be configured with a low power consumption RAM (C-MO8RAM) and a memory backup power source (such as a Li battery).
It is not limited to these.

Next, the principle of obtaining correction data will be explained with reference to FIG. First, let the characteristic straight line of the concentration value with respect to the input voltage assumed for calculation be (1), and the characteristic straight line of the concentration value with the input voltage according to the concentration of an arbitrary object to be measured be (''), and further,
4 obtained by measuring the object to be measured with a concentration of O
A characteristic straight line I is obtained by shifting the straight line (ID) by 0 minutes.The concentration value of the straight line I for any voltage is dl, and the same straight line (
If the concentration value of I) is dl, and the concentration value in the straight line for a certain voltage is DT, and the concentration value of the straight line (D is D'T), then DT wealth d2/dt (D'T-do) becomes The comma correction value d2/di and the zero correction value dO can be obtained from the conversion formula.

Since the concentration meter of this invention is constructed as described above, the parameter dO1l/dx (or di・dl) is set to 2.
As a digital value, the memory card 11 can be saved even when the power is cut off.
By simply storing 4 in the storage unit, you can correct the measured concentration value of any object to be measured and obtain an appropriate concentration value, unlike conventional products, which must be done every time the power is turned on. This has the advantage of eliminating the need for complicated volume adjustment and concentration value calibration work.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure is a graph showing the principle of obtaining correction data. In the figure, 1 is the object to be measured, 2 is the light emitting element, 3 is the light receiving element, 4 is the central processing unit, 5 is the recording or display section, 6 is the correction data processing section, and γ is the memory state that is maintained even when the power is cut off. A storage unit that can hold data, 8 is an operation unit. Patent applicant Konishiroku Photo Industry Co., Ltd. Agent Patent attorney Hayabusa Sakaguchi Shodensei

Claims (1)

[Claims] The correction data for correcting the gamma value and zero value is stored in a storage unit that can maintain its memory state even when the power is turned off, and the concentration measurement value of any measured object can be corrected using this data to obtain the calibration measurement value. A densitometer characterized by having a measured value correction section that obtains a measured value.