JPH0312617A - Image pickup printing device - Google Patents

Abstract

PURPOSE:To make an invariably accurate focus adjustment even when the reflection factor of a subject is greatly different by providing a previously set correction coefficient in response to the reflection factor of the subject and making corrections with distance data obtained by a distance arithmetic circuit. CONSTITUTION:A mode switching means 22 has the previously set correction coefficient corresponding to the reflection factor of the subject and a correcting means 20 corrects a distance signal with the selected correction coefficient in response to the operation of an operation button 23. A correct distance signal is outputted to a lens driving circuit 25 to control the operation of a motor 26 for adjusting the focus of an image pickup lens. Consequently, invariably correct distance data is obtained without being affected by the reflection factor of the subject, so the focus of the image pickup lens can be adjusted correctly for any subject and a sharp image can be printed out.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides an autofocus function that captures an image on a blackboard, a whiteboard, a landscape image, etc., and prints it out on paper. The present invention relates to an imaging printing device equipped with the following.

(Prior Art) The present applicant has disclosed a device for reading an image on a blackboard or a whiteboard, or a landscape image, etc. using an image scanner having an imaging lens and printing it out on paper, in Japanese Patent Application No. 13796/1983. There is an imaging printing device proposed in . As mentioned above, this device captures various images using the imaging lens, but while images of landscapes and people are three-dimensional images, images on blackboards and whiteboards are two-dimensional images, so bits are applied to the entire image. Accurate bit alignment is required.

As a means to automate the bit alignment function of such imaging lenses, it is widely used in 35 mm cameras.
A triangulation-based distance detection means using an infrared beam is considered. As is well known, this distance measuring means using the triangulation method uses a light beam for distance measurement directed toward the subject, that is,
A beam of infrared rays is emitted, the light reflected from the subject is received by a light receiving section, and the distance from the position of incidence on the light receiving section to the subject is determined by calculation.

Such distance detection means has a characteristic that a difference in distance measurement results occurs when the intensity of reflected light changes significantly. In other words, if the reflectance of the subject is large and the reflected light is much stronger than the standard value, the measurement result will be that the object is at a closer distance than the distance measured using the reflected light of standard strength (hereinafter referred to as reference light). . On the other hand, if the reflectance of the subject is low and the reflected light is much weaker than the standard value, the measurement result will be that the subject is at a longer distance than the distance measured by the reference light.

Normally, distance detection means used in 35 mm cameras and the like are used to capture landscapes, people, etc., so the reflectance of the subject is set at around 38%.

In other words, the setting is such that the correct distance can be measured when the reflected light from the subject having a reflectance of about 38% is received. Here, the imaging printing device also captures images on blackboards and whiteboards, but the reflectance of the blackboard is 1.
The reflectance of the white board is as low as about 0%, and the reflectance of the white board is as high as about 90%. Therefore, for the image on the blackboard, the measurement result will be that the distance is farther than the actual distance, and for the image on the whiteboard, the measurement result will be that the distance is closer than the actual distance. turn into. Since the bit adjustment of the imaging lens is performed based on these measurement results, the bits become loose and the image becomes unclear.

(Problems to be Solved by the Invention) As described above, conventional distance measuring means set distance measurement information only using a reference chart having a reference reflectance, and the difference between objects to be measured, that is, Errors in ranging information that occur when reflectances differ are not taken into account, making accurate bit adjustment difficult.

The purpose of the present invention is to
To provide an imaging printing device that can always obtain correct distance information, perform accurate bit adjustment, and obtain clear images.

[Structure of the invention]

(Means for Solving the Problems) An imaging printing device according to the present invention irradiates a distance measuring light beam onto a subject and receives reflected light from the subject, thereby determining the distance to the subject based on the principle of triangulation. It has an arithmetic circuit and adjusts bits of the imaging lens based on the output of the arithmetic circuit, and has a plurality of correction coefficients set in advance corresponding to the reflectance of the subject. and a correction means that corrects the distance data obtained by the distance calculation circuit using the switched correction coefficient.

(Function) In the present invention, a plurality of correction coefficients are set in advance in accordance with the reflectance of the subject, the correction coefficients are switched according to the subject, and the correction coefficients are calculated based on the incident position of the reflected light from the subject. Since the measured distance data is corrected, it is possible to always obtain the same accurate distance to the subject as in the case of distance measurement using reference reflected light, and as a result, a clear image can be obtained with accurate bit adjustment.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

First, the distance measuring means used in the present invention will be explained with reference to FIG.

Reference numeral 11 denotes a light emitting element that generates a light beam for distance measurement, and for example, an infrared light emitting LED that emits an infrared light beam 111 is used.

This light emitting element 11 directs the infrared light beam 11! to a subject 13 such as a blackboard through a projection lens 12. irradiate.

Reference numeral 14 denotes a semiconductor device detection element, which is provided at a position that maintains the base line length B with respect to the light emitting element 11. This semiconductor device detection element 14 receives an object 13 through a light receiving lens 15.
The reflected light 11b is incident, and the analog output 1 corresponding to the incident position, that is, the distance l to the subject 13
．． , yielding I2.

Next, the main structure of the present invention will be explained with reference to FIG.

I7 is a microcomputer (hereinafter referred to as microcomputer)
It generates operation timing commands for various circuits to be described later, and also has various calculation functions. The light emitting element 11 emits light by the operation of the lighting circuit 18. Further, the analog output 1 from the semiconductor device detection element 14.
, I2 are input to the distance calculation circuit 19, and this analog output 1. , I2, an m-bit (4 bits in the example shown) digital distance signal corresponding to the distance l shown in FIG. 6 is calculated. This digital distance signal is
The signal is applied to a correction means 20 realized by a microcomputer 17. In addition, the lighting circuit 18 and the distance calculation circuit 19
are operated by timing commands generated from the timing control means 21, respectively. 22 is a mode switching means;
It has a plurality of correction coefficients, which will be described later, which are set in advance in accordance with the reflectance of the subject 13, and provides an arbitrary correction coefficient to the correction means 20 in response to the operation of a mode switching operation button (switch) 23.

The correction means 20 corrects the digital distance signal using the selected correction coefficient. This corrected correct distance signal is output to the lens drive circuit 25, and controls the operation of the bit adjustment motor 26 of the imaging lens.

Next, the above correction coefficient will be explained using FIG.

FIG. 2 shows the relationship between the distance to the object and distance measurement data. The solid line in the figure shows the change in distance measurement data 5D(N) when the reflectance of the subject is 38% (landscape, person, etc.), and it is possible to obtain accurate distance measurement data corresponding to the subject distance. . Hereinafter, distance measurement for a subject with a reflectance of 38% will be referred to as a reference mode.

Furthermore, the broken line indicates a change in distance measurement data S D (B) when distance measurement is performed on an object such as a blackboard with a reflectance of about 1σ%. Hereinafter, this distance measurement will be referred to as blackboard mode. In this blackboard mode, since the reflectance of the subject is low, the distance measurement data is larger than in the reference mode.

That is, distance measurement data S D (B) indicating whether the subject is farther than the original distance is generated.

Further, the dashed-dotted line indicates a change in the distance measurement data S D (W) when a subject such as a white board is measured with a reflectance of about 90%. Hereinafter, this distance measurement will be referred to as white board mode.

In this white board mode, the reflectance of the subject is high, so the distance measurement data is smaller than in the standard mode.

That is, distance measurement data S D (W) indicating whether the object is closer than the original distance is generated.

Here, in order to make the distance measurement data SD (81) in the blackboard mode and the distance measurement data SD (W) in the whiteboard mode equal to the distance measurement data SD (N) in the standard mode, the following correction calculation is performed. Let's do it.

In case of blackboard mode: 5D(B)x(1-α)=SD(N) In case of whiteboard mode: 5D(W)x(1+β)=SD(l11) Therefore, α and β that satisfy the above formula are determined by experiment. Then, using the above formula, a value close to the accurate distance measurement data S D (N) in the reference mode is obtained by taking these α and β into consideration.

According to the applicant's experiments, it was found that α = β = 0.04 is optimal. In addition, the correction coefficients (1 - α) and (1 + β) are stored in the mode switching means 22 in FIG. The corresponding correction coefficient is selected according to the switching operation by the mode switching operation button 23 and is provided to the correction means 20.

Then, in the correction means 29, the digital distance signal outputted from the distance calculation circuit 19 is multiplied by the given correction coefficient to perform correction calculation according to the above equation.

Next, referring to FIGS. 3 and 4, a specific configuration of the imaging printing apparatus will be explained.

31 is a main body case, and an image scanner 32 for imaging shown in FIG. 4 is provided inside this case.

The image scanner 32 mainly includes an imaging lens 33 and a line image sensor 34.

The imaging lens 33 is installed on the side surface of the main body case 31, as shown in FIG. In addition, the imaging lens 33
A reflecting mirror 35 is provided behind the mirror (to the right in FIG. 4), and above it a focusing plate 36 made of ground glass or the like is provided.
is provided so as to be slidable toward the right in the figure.

The line image sensor 3a slides together with the focus plate 36 when the focus plate 36 slides to the right in the drawing, scans the image to be formed on the focus plate 36, and converts it into information. It is attached to the side part of the plate 36. This focusing plate 36 is driven in the sliding direction by a motor (not shown) or the like. Further, the line image sensor 34 and the focus plate 3 slide together.

Here, in the line image sensor 34, the above-mentioned slide is a sub-scan, and during this sub-scan, the line image sensor 34 continues main scan in a direction perpendicular to this, and scans the image to be formed on the focus plate 3G.

Reference numeral 38 denotes a viewfinder, which is provided above the focus plate 36 and is composed of an image enlarging lens 39 on the focus plate 36 and a transparent plate 40 provided at the top opening of the main body case.

Reference numeral 41 denotes a blocking plate, which is provided between the focus plate 36 and the magnifying lens 39 so as to be slidable toward the right in the figure, and when the line image sensor 34 scans, the transparent plate 40
The external light from the lens is blocked from the focusing plate 36 side. The sliding of the shutter closing plate 41 is driven by the aforementioned motor via a cam mechanism or the like prior to the sliding of the focusing plate 36.

Returning to Figure 3, 45 is the copy button, and the main case 3
1 is installed on the top surface of the paper 4, and when turned on, the printer 46 built in the main body case 31 is operated, and the paper 4
Print out 7.

The operation buttons 23 for mode switching explained in FIG.
The corresponding mode (reference, blackboard, or whiteboard mode) is selected by turning one of them on.

12! 1 is a light projecting window, and 151 is a light receiving window, which are arranged to face the corresponding ones of the light projecting lens 12 and the light receiving lens 15 shown in FIG. 1, respectively. That is, the distance measuring light ray Its shown in FIG.
The reflected light 11b from the subject 13 passes through the light receiving window 15M and the light receiving lens 15, and is input to the semiconductor device detection element 14.

For example, as shown in FIG.
0 and captures an image on the board 4g.

Here, for the above-mentioned imaging, first, the mode switching operation button 23 is operated to select a mode corresponding to the board 49. For example, if the board 49 is a blackboard, the mode is switched to blackboard mode. By this operation, the mode switching means 22, which is a function of the microcomputer 17, provides the correction coefficient (l-α) corresponding to the selected mode to the correction means 20.

In addition, the microcomputer 17 operates the lighting circuit 18, and the distance measuring light ll! from the light emitting element +1! irradiate the subject. The reflected light 11b from the subject 13 is incident on the semiconductor device detection element 14, and an analog output is generated according to the incident position!
, , 12. At this time, the distance calculation circuit 19 is also in an operating state, and outputs an m-bit digital distance signal corresponding to the subject distance l to the microcomputer 17 based on the analog outputs II and I2.

Since the subject 13 is a blackboard with low reflectance, the digital distance signal has a larger value than the standard data SD(^), which is correct distance data, as shown in FIG.
In other words, the distance measurement data S D has a value indicating whether the distance is far.
(B) becomes. The correction means 20, which is a function of the microcomputer 17, performs correction by multiplying this digital distance signal by the correction coefficient (l-α) described above. Through this correction, accurate distance data close to the reference data S D (N) shown in FIG. 2 can be obtained. Since the lens drive circuit 25 is controlled by this accurate distance data, the motor 2
6 allows the bits of the imaging lens 33 to be accurately aligned with the image on the board 49.

In this way, the bit adjustment of the lens 33 is automatically performed, and the image on the board 49 is incident through this lens 33 and is focused on the focusing plate 36 via the reflecting mirror 35.

The user turns on the copy button 45 while monitoring this image through the viewfinder 38. By this operation, the closing plate 41 first slides, and the transparent plate 4G
Blocks outside light from entering. Next, the focus plate 36 and the line image sensor 34 attached thereto slide to scan the image to be formed on the focus plate 36.

Image information generated by the image sensor 34 through the above scanning is binarized and output to a printer 46. Therefore, the printer 46 prints out on paper 47 an image based on the binarized information.

In this way, the image printed out on the paper 47 becomes clear because the bits of the imaging lens 33 are adjusted correctly.

Although the above explanation is for the blackboard mode, the same applies to other modes as well. That is, if the subject 13 is a white board, a landscape, or a person, the mode switching operation button 23 is used to switch to the white board mode or the reference mode. Through this operation, a correction coefficient corresponding to the switched mode (the reference mode is 1) is selected and multiplied by the digital distance signal in the correction means 20. Therefore, without being affected by the reflectance of the subject,
You can always get accurate distance data.

〔Effect of the invention〕

As described above, according to the present invention, correct distance data can always be obtained without being affected by the reflectance of the subject, so the bits of the imaging lens can be adjusted correctly for any subject, and clear images can be obtained. can be printed out.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the imaging printing device according to the present invention, FIG. 2 is a characteristic diagram showing the relationship between the distance to the subject and distance measurement data in each mode, and FIG.
A perspective view showing the external shape of the imaging printing device shown in the figure;
4 is a cross-sectional view showing the optical system of the device shown in FIG. 3, FIG. 5 is a perspective view showing how the device shown in FIG. 3 is used, and FIG. It is an explanatory diagram showing an example. 111...Ray of light for distance measurement, llb...Reflected light, 13
・Subject, 19..Distance calculation circuit, 20..Correction means,
22...Mode switching means, 33...Imaging lens. Compliance with IU] Suichitate

Claims (1)

[Claims] (1) It has a distance calculation circuit that calculates the distance to the subject based on the principle of triangulation by irradiating the subject with a distance measuring light beam and receiving the reflected light from the subject, and based on the output, the imaging lens An imaging printing apparatus that performs bit adjustment, comprising: a mode switching means having a plurality of correction coefficients set in advance corresponding to the reflectance of the subject and switching the correction coefficients according to the subject; and the distance calculation circuit. An imaging printing apparatus comprising: a correction means for correcting the obtained distance data using the switched correction coefficient.