JPH07193682A - Reader - Google Patents

Abstract

PURPOSE:To easily confirm a reading range without use of an exclusive original platen or the like by emitting an optical mark utilizing the difference from the luminance to four corners equivalent to the reading range of an object to be read by the reader. CONSTITUTION:A mark emission section 1 provided to four corners of the reader main body 8 projects optical marks 2 at four corners adjusted corresponding to a reading range on a desk on which an original 5 is placed and the user sets the original 5 to a range frame 6 of the marks 2. When the reader 8 starts reading, a main scanning device 7 returns to a read start position to start reading and applies sequentially scanning from the end of the original 5 in a line in the main scanning direction 9. The line state picture is given to a line image sensor 3 via a lens 4, which converts one line array shaped picture element into an electric signal corresponding to each picture and the signal is transferred to an external processing circuit. Thus, the reading range is easily confirmed without use of a finer of the reader and an exclusive original platen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading device (image scanner device) for reading characters and images and converting them into digital data.

[0002]

2. Description of the Related Art As a widely used conventional reading device, a flat head type reading device having a transparent plate on which a document is placed, and an image sensor scans the underside, is used by placing the device on the document surface. Typical devices are a handy scanner device that scans an image sensor by a human hand, and a camera-type reading device that indirectly reads a document. Of these, the camera-type reading device can also read irregularly-shaped originals, thick books, and even vertically mounted objects such as whiteboards. Compared to other reading devices, the size, orientation, flatness, etc. This has the advantage that there are few restrictions on the subject.

An example of a conventional camera type reading device is shown in FIG. The camera-type reading device includes a line-type image sensor 3 in which reading elements are integrated in an array, a lens 4 for forming an image of a document as a subject on the surface of the image sensor, and the line-type image sensor 3. And a main scanning mechanism 7 for sequentially scanning an image of a two-dimensional read original by changing the projection position.

In order to read a document with a camera-type reading device, it is necessary to first confirm the reading range. The conventional example shown in FIG. 4 is a commercially available camera-type reading device, and the reading range is confirmed by looking through the finder 17 made of a reflecting mirror.

Further, in the camera type reading device, the device main body including the lens and the scanning mechanism and the image sensor is fixed at a position separated from the original by a predetermined distance (for example, 40 cm) during a specific time required for the main scanning. Need to do so. Therefore, a stand is required in addition to the function of confirming the reading range.

Although an example of using a two-dimensional image sensor, there is JP-A-4-10857 as an invention of a reading device using a stand. The apparatus body according to the present invention is not provided with a reading range designating means. A two-dimensional image sensor can read a two-dimensional image in a shorter time than a line type image sensor. Therefore, in the present invention, the range is specified by checking the read image as needed. However, a two-dimensional image sensor satisfying a resolution sufficient for reading a document is very expensive. Therefore, in this patent, a plurality of inexpensive image sensor elements are combined in a mosaic manner to improve the resolution. Consistency becomes a problem when synthesizing images read by individual elements, and it is difficult to construct a mass-produced device inexpensively.

The time required for reading is determined from the reading resolution, the brightness of the original, the sensitivity of the image sensor and the transfer speed, and the optical system of the apparatus, and is 1 to 30 seconds. The distance is determined by the performance of the lens and the size of the reading range.

In the reading apparatus described in FIG. 4, in order to fix the apparatus main body and the original during the reading time, a fixing means is secured by providing a stand as seen on three legs.

Further, as a commercial product, there is a reading device having a dedicated document table and a stand. This apparatus is a system in which reading is performed from the top of a document table, and an outline is shown in FIG. In order to determine the reading range with this device, a mark indicating the reading range frame 17 is preliminarily attached to the document table 18, or a dedicated display is incorporated in the reading system, and the user is placed on the document table 18. Check the read range by aligning the original with the mark or by looking at the original displayed on the display.

Japanese Patent Laid-Open No. 60-148272 discloses an example of an invention of a reading device which writes a reading range frame as a color mark on a document and detects the mark to define the reading range. The present invention has an advantage that the reading range can be reliably specified on the original, but a mark must be written on the original, and the frame cannot be surely detected due to variations in writing. Further, there is an invention which defines a reading range by providing a three-dimensional frame on a document and moving a handy scanner in the frame.
In the official gazette. In this invention, since the frame that is directly placed on the original is used to specify the reading range, it is possible to specify the reliable reading range. If it is not possible to place them, it may not be possible to reliably specify the range.

[0011]

There are the following problems when a document is read as a work on a desk by using the camera type reading device described in the prior art.

When reading a document on a desk with a device incorporating a finder, it is necessary to look into the finder incorporated in the device in order to check the reading range. It is difficult to check the reading range while sitting down because you are looking into the viewfinder of the fixed device.
Complicated work is required to use the reading device.

Further, in a device in which the positional relationship between the original table and the reading apparatus main body is fixed by a dedicated original table and arm, and the original is placed and read in accordance with a frame written in a predetermined position on the original table. Since the ratio of the document table and the stand to the whole device is larger than that of the reading device main body equipped with the image sensor and the main scanning mechanism, the whole device becomes large and it is necessary to secure a place to install the document table on the desk. , Is a problem.

[0014]

A reading device according to the present invention is provided with a means for irradiating a mark for designating a reading range, and when confirming the reading range, the reading range among the objects to be read from the device is read. The reading device irradiates an optical mark using the difference in brightness to the corner corresponding to
Specify the reading range. By doing so, the reading range can be confirmed only by looking at the optical mark radiated from the device to the document normally placed on the desk, and the reading device which reduces the complexity for confirming the reading range is provided. .

[0015]

1 shows an embodiment of a reading device according to the present invention. The reading device body 8 includes a line-type image sensor 3,
In addition to the lens 4 for forming the image of the read image on the image sensor surface, the main scanning mechanism 7 for main scanning the image on the line type image sensor, and the mark irradiation unit 1 which is a feature of the present invention. It

Next, the overall operation of the reading apparatus according to the present invention will be described with reference to FIG. 1 and FIG. 2 showing a typical usage pattern. When this apparatus is operated, first, the optical mark 2 is projected from the mark irradiation unit 1 on the desk 21 on which the original document is placed in FIG. The user places the original 5 to be read according to the output optical mark 2. When the setting of the original 5 is completed, the main body 8 of the apparatus starts reading.
In the reading device in FIG. 1, the main scanning mechanism 7 returns to the reading start position and reading is started. Reading is sequentially performed in the main scanning direction 9 from the edge of the original 5, and a linear image is formed on the surface of the line image sensor 3 through the lens 4. In the line-type image sensor 3, the pixels in an array forming one line each convert into an electric signal corresponding to an image and transfer the electric signal to an external processing circuit.

As a mechanism for performing the main scanning, there are a mechanism for stopping the scanning for each line and a mechanism for continuously performing the scanning without performing the stop scanning. In the former mechanism for stopping, when the processing for one line in the image sensor has a break, and in the case where stop scanning is not performed, the operation for main scanning is continuously performed and the line next to the read original is read. The corresponding images are sequentially projected on the image sensor. The image reading in line units by the image sensor and the operation of main scanning are repeated to read the document within the reading range frame 6 indicated by the optical mark 2.

The above is the outline of the operation, but the description will proceed according to a more specific device. As a line type image sensor that is an element for reading an image,
A CCD linear image sensor having a photo cell array in which 2088 light receiving elements are integrated in a length of about 35 mm and two rows of CCD charge transfer registers is commercially available. The process of capturing 2088 point image data in the longitudinal direction of the sensor consists of line-by-line accumulation, charge transfer, and sample hold of analog signals output according to each point image. The storage time required for each line changes depending on the sensitivity of the sensor and the brightness on the sensor surface, but it takes 1 to 8 milliseconds in this embodiment, and the line type image sensor transfers it to an external processing circuit. If the rate is 2 MHz, the time required for one line is about 2 msec to 10 m
Between seconds.

As a lens provided on the line-type image sensor to form an image, the focal length is 4 in this example.
A glass lens having a diameter of 0 mm and a diameter of 16 mm is used.

As an example of the main scanning mechanism 7, a reflecting mirror provided for performing main scanning in a direction perpendicular to the longitudinal direction (line direction) of the line image sensor 3 has a size determined from the angle of view. It has a function to induce rotation according to main scanning. As a mechanism for inducing rotation of the reflecting mirror, a DC motor is used as a power source to decelerate by a reduction mechanism.
The rotation speed corresponds to the main scanning speed per line of the image sensor. If, for example, 3000 line main scanning is performed using the line image sensor 3 described above, the time required for one main scanning depends on the brightness of the illumination, the sensitivity of the image sensor, and the transfer time. Seconds.

During the above-mentioned time required for the main scanning, a desired high-quality read image cannot be obtained unless the positional relationship between the reading apparatus main body and the document is fixed. For this reason, a method for fixing the reading device to the document while confirming that the reading range is appropriate is required. As described above with reference to FIG. 2, the present invention secures the apparatus body to the document 5 with the configuration of the embodiment in which the apparatus body 8 is combined with the stand 20, and directs it to the corner corresponding to the reading range. By irradiating the optical mark 2 depending on the difference in brightness, the reading range is confirmed while directly looking at the original.

A typical example of the optical mark irradiation unit will be described. As shown in FIG. 1, the optical mark irradiation units attached to the apparatus are provided at four positions of the reading apparatus main body 8, and in this embodiment, the directions are adjusted so as to irradiate the four corners of the document 5. The illuminated optical mark 2 corresponds to the reading range of the reading device. Then, the portion within the quadrilateral range frame 6 connecting the marks irradiated on the document surface from the four irradiation portions is the target of reading. By providing such a mark irradiating section and irradiating an optical mark, the reading range can be confirmed on the document surface.

As shown in FIG. 3, the structure of the mark irradiation section is as follows.
It is composed of a light emitting body 10, a lens 11 and a circuit 12 for driving the light emitting body 10. The light 13 emitted from the light emitting body 10 becomes a parallel light beam 14 by the lens 11 and is projected as a mark on the document surface.

Further, a specific structure of the mark irradiation section will be described. If a semiconductor laser of visible light (wavelength 670 nm) is used as a light source as a light emitter for irradiating a mark, a small and light mark irradiator can be configured.
The semiconductor laser has a diameter of 9 mm, a thickness of 5.1 mm, and an output of 1 mW. The lens is for converting laser light into parallel light rays and has a focal length of 3.6 mm and is made of glass on the market. In addition, LE with microlens
If D is used, the light emitter and the lens can be designed as one component, and the configuration can be further simplified.
As a circuit for driving the light emitter, a current of 85 mA is secured with a power supply voltage of -12V.

The above is a description of a typical mark irradiation unit, but the reading range can be easily confirmed by using another example of the mark irradiation unit according to the present invention as described below. It is not always necessary to provide four mark irradiation portions, and the shape of the mark does not have to be a spot. For example, a mask screen with a slit-shaped window is used after the light emitter to make the shape of the optical mark linear, or the shape of the optical mark output from the mark irradiation unit by mechanical scanning using a polygon mirror. Even by using a linearly visible object, the reading range can be clearly shown by setting the range surrounded by the linear optical marks as the reading range.

[0026]

According to the reading apparatus of the present invention, despite the indirect reading method in which there are few restrictions on the original document, the original document can be read without looking into the finder incorporated in the apparatus. Since the reading range can be easily confirmed by the optical mark output on the document without using a table, it is effective in reducing the complicated work required for reading.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a reading device according to the present invention.

FIG. 2 is a perspective view showing a usage pattern of the reading device according to the present invention.

FIG. 3 is an explanatory diagram illustrating an optical mark irradiation unit according to the present invention.

FIG. 4 is a perspective view showing a conventional reader.

FIG. 5 is a perspective view showing another conventional reading device.

[Explanation of symbols]

 1 mark irradiation part 2 optical mark 3 line type image sensor 4 lens 5 document 6 range 7 main scanning mechanism 8 device body 9 main scanning direction 10 light emitter 11 lens 12 drive circuit 13 light 14 ray 15 finder 16 reflector 17 reading range Frame 18 Platen 19 Illuminator

Claims (1)

[Claims] 1. A reading device which indirectly captures an image and converts it into digital data, comprising a mark irradiation means for irradiating an optical mark to a position corresponding to a reading range.