JPS63166362A - Image reader - Google Patents

Abstract

PURPOSE:To attain the detection/alarm display of mis-loading of film with loaded wrong side out by providing a focus means for both sides of an original film to a photoelectric transducers for reading image so as to compare both the read outputs. CONSTITUTION:If the original film 20 is loaded in error with wrong side out, that is, if a film emulsion face is loaded to the side of a halogen 3 and the base face is loaded toward an image forming lens 21, since the reader is not in focus with the picture with an optical path adjusting plate I102 inserted, the total sum SI of the absolute value of the difference in the output values of adjacent picture elements is a small value and since the reader is in focus with the picture with the optical path adjusting plate II103 placed, the total sum SII of the absolute value of the difference of outputs of adjacent picture elements is a large value. That is, in comparing the absolute values of the values SI, SII, mis-loading of the film is detected. Thus, in case of SI>SII, an LED lamp 110 applying alarm display of film mis-loading is lighted and the succeeding processing is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image reading device, and particularly to a photoelectric conversion type image reading device for reading an image from a transparent original.

[Conventional technology]

Conventionally, in this type of image reading device, the transparent original, such as film, is often small, such as a standard 35 mm size, and in order to read such a small size original, a high magnification magnification is required. It was necessary to use an imaging optical system.

[Problem that the invention seeks to solve]

For this reason, the depth of field at the position of the original film in this type of imaging optical system is extremely narrow, and the operator may accidentally load the original film with the base and emulsion sides reversed. In this case, not only will the output image be left and right opposite to the original image, but it will also be
In the case of mm color film, the position of the original image will shift by about 0.14 to 0.17 mm), and the position of the photoelectric conversion element (e.g. CCD line image sensor) that reads the image information will not be in focus. There was a problem that the resulting image was unfocused (defocused) and could not be used.

To give an example of 11 objects, for example, 35 mm of the horizontal screen size of 36 mm of a 35 mm film is imaged at the same magnification using a microlens with a focal length of 50 mm F4, and a pixel size of 7 μm x 7 μm is formed with 5°000 pixels. C.C.
When reading with a D-line image sensor, if the image position shifts by the film thickness of 0.14 mm, the diameter of the circle of confusion (diameter of the blur) at the CCD-line image sensor is 17.
．． The thickness is 5 μm, corresponding to 25 pixels of a CCD, and is completely unusable.

The present invention has been made in view of the problems of the prior art as described above, and in order to eliminate the above-mentioned drawbacks, it is an object of the present invention to provide a mechanism for detecting incorrect loading of film. There is.

[F-stage to solve the problem] Therefore, in the present invention, the 9' subconversion element for reading the original image is provided with means capable of focusing on both sides of the original film, and the image information of both is provided. By comparing and calculating the human power of the signal, it is configured to detect/warn incorrect loading of the front and back sides of the film.
This is what we are trying to do.

[Effect]

With the above configuration, a warning is displayed in the case of incorrect loading of the original film, so that the operator can immediately take appropriate action.

〔Example) The present invention will be described above based on examples.

FIG. 1 shows a perspective view of an optical @(L) cross-section of an embodiment of an image reading device that can pass through a document of the present invention.

(Structure) The image reading device shown in the figure performs main scanning using a CCD line image sensor 22 as a photoelectric conversion element, and performs sub-scanning by moving the film stage 15 to read an image of a document 20. Red, green, and itt colors (hereinafter R, G) are arranged behind the lamp 3.
, B)) is switched three times to complete the reading of one document image.

Here, reference numeral 1 denotes a Heas base plate, on which a die-cast base plate 2 is disposed for the purpose of rigidity, vibration isolation, etc. from the film stage 15 to the reading section by the CCD 22. Reference numeral 3 denotes a halogen lamp serving as a light source for illuminating the original, and the light from this lamp 3 illuminates the original film 20 through illumination lenses 4 and 4a. This illumination method is called "Kohler illumination" and has the advantage that the film surface can be uniformly illuminated regardless of the size and shape of the halogen lamp 3. A fan 5 is used to cool down the heat generated by the lamp 3.

When the color filters 6R16G and 6B are on the optical path, only the image of the corresponding color is read.

Each of the filters 6R16G and 6B is mounted on a filter base plate 7, and the filter base plate 7 is movable in left and right directions perpendicular to the optical axis by a linear slide mechanism 8. That is, the filter base plate 7 is connected to the timing belt 1o by the connecting member 9,
Timing belt 10 is connected to step motor 12 via pulley 11. Further, the filter base plate 7 has respective notches 7a carved in portions corresponding to the positions of the respective color filters, and a photocoupler 13 for detecting the positions of the notches is disposed. Therefore, when the motor 12 is driven to move the timing belt IO, the filter base plate 7 is moved left and right by the linear slide mechanism 8, and the photocoupler 13 is inserted into the notch 111 of the filter base plate 7.
is detected and the rotation of the motor 12 stops [I].
Necessary color filters are arranged on the optical path.

Further, 14 is a ball screw for moving the film stage 15, and is connected to a step motor (not shown). The film stage 15 is held by a pair of parallel linear guides 16, and can be moved left and right by rotation of the ball screw 14. A film holder 17 is provided on the top of the film stage 15, and two glasses 18 are placed on top of the film stage 15.
The structure is such that the document film 2o sandwiched between the angles 19 and 20 can be loaded therein. FIG. 2 shows an enlarged exploded perspective view of this part.

Returning to FIG. 1 again, reference numeral 21 denotes an imaging lens, which is used to form an image on the filter 20 onto a CCD line image sensor 22h.

23 is a CCD circuit board, 24 is a shield cover, 2
5 is a base plate for fixing the position of the CCD 22.

The part indicated by A is a film loading error detection mechanism which is a feature of the present invention, and a pair of optical path adjustment plates I/ll1 are mounted on the main plate 101.
02/103 is installed. The optical path adjustment plate 1102 has its original imaging optical system (see FIG. 3 and FIG. 4, respectively).
1)/(2), the surface of the original film 20 on the side of the imaging lens 21 (in Fig. 3.4, it is simply represented by one lens) or the CCD line image sensor. The other optical path adjusting plate 11103 is a plate glass having a thickness such that it can be focused on the film 20.
The surface of the three halogen lamps above is a plate glass having a thickness such that it can be focused on the CCD line image sensor 22. Note that if there is a sufficient difference in thickness between the two optical path adjustment plates 1102 and 1103, it is acceptable to omit the optical path adjustment plate 1102 and make the optical path adjustment plate [103] thinner. do not have.

The base plate 101 is attached to the linear slide mechanism 104 and is connected to the timing belt 1 via the connecting member 105.
It is connected to 06. Timing belt 106 is connected to step motor 108 via pulley 107. In addition, the main plate 101 is made of a 2gl plate I/ll for each optical path.
An odocoupler 10 (having each notch 101a at a position corresponding to 102/103 and for detecting this notch)
9 are arranged.

The method of switching these optical path adjusting plates I/l 1102/103 is the same as the switching of each color filter 6R16G, 6B, and the step motor 108 is driven to move the base plate 101, and when the switching of the optical path BJ is completed. in,
Photocoupler 109 or the notch 1 on the main plate 101
The configuration is such that the motor 108 is stopped upon detecting 0 Ja. Incidentally, reference numeral 110 shown at the right end in FIG. 1 is an LED lamp for displaying and warning the operator when erroneous loading of the original film is detected.

FIG. 5 shows a configuration block diagram of the control circuit in FIG. 1. In the figure, 6a is the motor 12 and its controller, 15a is the motor (not shown) of the film stage 15 and its controller, and 108a is optical path adjustment. Board I/[1
02/103 drive motor 108 and its controller, 22a is a driver for the CCD line sensor 22,
50 is a sequence controller, 51 is a controller switch thereof, 52 is an amplifier Σ and an A/D converter, 5
3 is a buffer memory, and 54 is an edge extraction processing circuit (described later).

(Operation) Next, the operation of the image reading apparatus configured as described above will be explained based on the operation sequence flowchart shown in FIG.

First, when you turn on the main switch (not shown): 5f,
The halogen lamp 3 in FIG. 5 lights up, and the fan 5 starts (step Sl). Next, two sheets of glass 18
．． 19, the original film 2o is held, and the film 20 is loaded into the film holder 17 with the emulsion side (where the original image is present) facing the combination lens 21 side (step S
2). Then, when a start switch (not shown) is pressed, the step motor 108 rotates in the direction that the optical path adjustment plate 1102 is on the optical path, and when it is on the optical path, the photocoupler 109 detects the notch 101a. to stop the motor 108 (step S3).

In this state, the surface of the film 2o on the imaging lens 21 side,
In other words, the image is formed on the CCD line image sensor 22 on the side of the emulsion containing image information.

Next, image information for 1 line and 2 minutes is read from the CCD line image sensor 22 (step S4), and this output signal is sent to the analog/digital (A/D) converter 5.
After digital conversion in step 3, “edge extraction processing”
54 (step S5). The edge extraction processing referred to here is the content shown in the operation sequence flowchart of FIG. 7, and is characterized by the sum of the absolute values of the differences between the output values of adjacent pixels.

Next, the motor 108 is driven and the optical path adjusting plate 1110 is
3 is placed at the optical path position (step S6). In this state, the surface of the film 20 on the halogen lamp 3 side,
1- That is, the pace side where there is no original image information is CC
The image is formed by the D line image sensor 22J. Here, as in the previous case, one line of image information is read from the CCD line image sensor 22 (step S7), A/D conversion 52 is performed, and then edge extraction processing 54 is performed.
The result, that is, the sum of the absolute values of the differences between the values of adjacent pixels is set as S (step S8).

When the optical path adjusting plate 102 is installed, edges of the focused image are extracted. In the focused image, the edges of the image are clearly visible, so there are many high frequency components.
Sl of the processing result becomes a large value. On the contrary, the optical path adjusting plate■
103, the D9.8TI image information present on the emulsion side of the film 20 will be imaged on the CCD line image sensor 22 in an out-of-focus state. In such an out-of-focus image, edge portions do not clearly appear, so when edge extraction processing 54 is performed on such an image, Srx as a result of the processing will have a small value.

1 [In contrast, if you accidentally load the original film 20 upside down, that is, if you load the film emulsion side on the halogen lamp 3 side and the heel side on the imaging lens 21 side. When passing through the light path A 1s1102, the image is out of focus, so Sl is a small value, and when passing through the light adjustment plate II 103, the image is in focus, so Sn is It becomes a large value.

That is, the above Sl and Sf! By comparing the absolute values of the values, it is possible to detect erroneous loading of the film as described above (step S9). In case of S,>S, LED lamp 1 displays a warning of incorrect film loading.
10 is turned on, and subsequent processing is stopped (step 510). Conversely, in the case of S,>S, after returning the optical path adjustment plate to step 102 (step 5it), each step 3
12 to 314, each R, G, B filter 6R.

6G and 6B are sequentially inserted to scan the film and perform regular image reading.

FIG. 7 shows the operating procedure of the "edge extraction process" described in m, and detailed explanation will be omitted.

(Other Examples) In addition, in the examples described in ml, each optical path, J1 board machining/
Although +1102/103 was disposed between the imaging lens 21 and the CCD line image sensor 22, it may also be disposed between the 11m film 20 and the imaging lens 21.

Alternatively, the imaging lens 21 may be extended by an amount equivalent to the thickness of the film 20 without using the optical path adjustment plate, or,
A similar effect can be obtained by moving the film 20 or the CCD line image sensor 22 in the direction along the optical axis.

Furthermore, in the embodiment, the original film 20
If it is detected that the document is loaded with the front and back sides reversed, the operation is unconditionally terminated after displaying the LED lamp 110, or as a special case, when the document image is intentionally input in reverse. Even if a warning is displayed by the LED lamp 110, if you press the start button (not shown) again,
It is also possible to configure it to perform image reading.

In this case, it is preferable to configure the image reading with the light adjustment plate 103 remaining in the optical path, since this will allow the image to be read in focus.

〔Effect of the invention〕

As described in detail above, according to the present invention, the photoelectric conversion element for reading one image is provided with focusing means for each of both sides of the original film, and by comparing the reading outputs of both sides, it is possible to prevent incorrect loading of the front and back sides of the film. It is now possible to detect/display a warning.

[Brief explanation of the drawing]

FIG. 1 is an optical axis cross-sectional perspective view of an embodiment of an image reading device to which the present invention is applied, FIG. 2 is an enlarged exploded perspective view of the document film holding part, and FIGS. Optical system (1). (2) FIG. 5 is a block diagram of the control circuit configuration in FIG. 1, FIG. 6 is an image reading operation sequence flowchart, and FIG. 7 is an edge extraction processing operation sequence flowchart. 3...Halogen lamp (light source) 20...
・Original film 22...CCD line image sensor (photoelectric conversion element)

Claims (2)

[Claims] (1) An image reading device that photoelectrically converts and reads image information of an original film, comprising a focusing means that focuses both sides of the film on a photoelectric conversion element, and the photoelectric conversion that reads from each of both sides of the film. a calculation means for calculating the focus of the focusing means from the output image information signal of the element; a detection means for detecting incorrect loading of the document film from the calculation result; and a display means for displaying the detected incorrect loading. An image reading device comprising: (2) The image reading device according to claim 1, wherein the focus calculation means uses an absolute value of a difference between output values of adjacent pixels in the photoelectric conversion element.