JPH0595449A - Image reader - Google Patents

Abstract

PURPOSE:To release an external device for exposure time and sensor moving time by executing coarse reading only at the main body of the reader in the case of coarse reading, storing image data in a storing means at the main body and transmitting the data from the storing means to the outside. CONSTITUTION:A start button 28 is pushed, reading conditions such as resolution and gradation or the like are set for prescan in the reader, and the reading of images is started. The read data are stored in a storage part 23. During this operation, there is no exchange with a host 26 and therefore, the host is not occupied. Afterwards, communication with the host 26 is turned to an enable state, a prescan starting instruction is received from the host 26, and the data stored in the storage part 23 are transmitted through an input/output part 24. Accordingly, the host 26 is occupied only for data transfer time, and the host 26 can be effectively used. When the instruction from the host 26 does not show prescan, normal reading is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device.

[0002]

2. Description of the Related Art Conventionally, this type of image reading apparatus is generally used by connecting to a host computer. At this time, various reading conditions such as reading resolution and reading range are read from the host. It is set by an instruction, and the start of reading is also instructed by the host. The image reading device instructed to start reading stores the read image in the memory of the reading device for one line or several lines, and transfers the image data in parallel with the reading operation. Also, when actually reading an image, in order to know where the image to be read is located, the entire readable range of the reading device is read in advance at a low density and displayed on the CRT screen of the host. I was grasping the image of the whole image. Hereinafter, the operation of reading the entire reading range at low density is referred to as prescan.

[0003]

However, when the image is read by this type of image reading apparatus, the host is often occupied from the start to the completion of the reading. Actually, the time required for reading is the exposure time for irradiating the original with a light source and performing photoelectric conversion by the reading sensor, or for the reading sensor to complete reading one line and move to the next line, or for reading. In the case of a model in which the sensor is fixed, it depends on the moving time for moving the platen, the communication time for transferring image data, and the like. In this case, which factor affects the actual reading time depends on various reading conditions, the performance of the interface with the host, the processing speed of the host computer itself, etc. Causes problems such as exposure time and movement time of the reading sensor.

Further, this is particularly remarkable in the case of reading a small amount of data to be captured as image data. The pre-scan described above is a rough reading with a low density, and since data is often read with a small number of gradations, the amount of image data to be captured is small. In this way, even during prescan, which is relatively frequently used,
The time for occupying the host is determined by the exposure time and the moving time of the reading sensor and the like, and there is a problem that the reading device occupies the time longer than the processing time in the host.

The present invention has been made to solve the above-mentioned problems, and an image capable of releasing the host occupied by the exposure time and the moving time of the reading sensor etc. during the prescan. It is intended to provide a reading device.

[0006]

In order to achieve this object, the image reading apparatus of the present invention does not use a rough reading means for reading the image of the entire reading area at a low density and an external device for starting the rough reading. When there is an instruction to start the rough reading from the outside, an instruction means for instructing to, a storage means for storing the image data read by the rough reading,
A transfer means for transferring the image data in the storage means to the outside is provided.

[0007]

The image reading apparatus of the present invention having the above-described structure does not use an external device at the time of rough reading but starts rough reading only by operating the reading apparatus main body, and temporarily stores the image data in the storage means inside the main body. Then, when a rough reading start instruction is given from the outside, the data is sent from there to the outside.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, the overall configuration of the reading apparatus will be described with reference to FIG. A guide shaft 2 and a guide plate 3 are attached to the frame 1 in parallel with each other with a predetermined gap. A reading unit 4 is arranged between the guide shaft 2 and the guide plate 3, and one side of the reading unit 4 is guided by the bearing 5 to the guide shaft 2 and the other side is a guide plate so that the reading unit 4 does not float. It is supported by sandwiching the toe 3. Moreover, the reading unit 4 is movable along the guide shaft 2. Frame 1 has a drive mode
A reading unit 4 is moved by a driving motor 7 via a wire rope 6. A glass cover 8 is attached to the frame 1, and the original platen glass 9 is fixed on the glass cover 8.

The control board 10 is for controlling the operation of the reading device, and is provided with a circuit for interfacing with a host as an external device and a connector 27, and is flat with the reading unit 4. (Not shown). The control board 10 is attached to the frame 1 together with the protective plate 11.
The frame 1, the upper cover 12 and the lower cover 13 are attached via a receiving rubber 14 fitted to the frame 1. A document retainer 15 is attached to the upper cover 12 to hold the document so that the document does not shift during reading. Further, a start button 28 for starting prescan reading is attached to the upper cover 12.

Next, the structure of the reading unit 4 will be described with reference to FIG. The reading unit 4 includes a light source 17 that irradiates the original 16 placed on the original table glass 9, and the original 1
Three mirrors 19 for guiding the reflected light from 6 to the imaging lens 18 are arranged at predetermined positions. Also, manuscript 1
An image forming lens 18 for forming an image of the reflected light from 6 on the CCD 20 is provided inside, and a lens bracket for supporting the CCD 20 at a predetermined position is arranged. Also, the light source 1
7, the mirror 19, the lens 18, and the CCD 20 are integrally configured as a unit, and the drive motor 7 scans under the original platen glass 9.

Next, the circuit configuration of the image reading apparatus of this embodiment will be described with reference to FIG.

First, the image signal photoelectrically converted by the CCD 20 is input to the A / D converter 21. Next, A
The image signal converted into digital data by the / D converter 21 is subjected to processing such as pixel thinning and density correction in the processing unit 22, and then temporarily stored in the storage unit 23, and the input / output circuit 24 as a transfer unit. Output to the outside. Further, the processing unit 22, the storage unit 23, and the input / output circuit 24 are CP
A switch controlled by U25 and operated by the start button 28 is connected to the cpu25.

Next, the operation of the image reading apparatus of this embodiment will be described with reference to the flowchart of FIG. First, the present image input device is set to the initial state after the power is turned on (step 1, hereinafter abbreviated as S1). Here, the initial state means that the reading unit 4 is set to the standby position and a command from the host 26 or an instruction from the start button for starting the prescan is maintained in a receivable state. Next, it is determined whether or not the start button 28 on the reading apparatus main body is pressed (S
2). If the start button 28 is pressed, the reading resolution, gradation, and reading range are set for prescanning (S3), and image reading is started (S4).
In this case, all the read image data is stored in the storage unit 23 in the reading device (S5).

Next, it is judged whether or not a read command is issued from the host 26 (S6). Also, if the start button 28 is not operated in S2, the process is similarly shifted to S6. If there is no read instruction from the host 26, the process returns to S2. If there is a reading instruction from the host 26, it is judged whether or not the content of the instruction means pre-scan (S7). The reading conditions such as the key are set according to the instructions from the host (S8), and normal reading is performed (S).
9). If the condition means pre-scan, the image data stored in the storage unit 22 is input to the input / output unit 2.
It is sent to the host 26 via S4 (S10).

Here, a normal reading operation will be described. The normal reading is a reading operation of a conventional image reading apparatus. First, a reading start instruction is received from the host 26, and various reading conditions are set based on the instruction. Next, the light source is turned on and the reading unit 4 is moved to the image reading start position. At this position, the image formed on the CCD 20 is photoelectrically converted to A
It is converted into digital data by the / D converter 21. Next, the image data for one line converted into digital data by the A / D converter 21 is temporarily stored in the storage unit 23. Since it is very difficult to output the data to the host 26 at the same timing as the operation of reading the data from the CCD 20, it is necessary to temporarily store the image data in the storage unit 23. Next, the reading unit is moved by one line and the image is read in the same manner. In parallel with reading, the image data in the storage unit 23 is sent to the host via the input / output unit 24. The image can be read into the host 26 by repeating this operation.

Next, the prescan which is a feature of the present invention will be summarized and described again. As mentioned earlier,
In the conventional reading method, since the image reading and the data transfer are performed at the same time, the host 26 is occupied both when the CCD 20 reads the image and when the reading unit 4 moves. In the case of the image reading apparatus of this embodiment, the prescan is performed by the following procedure as described in detail above.

First, the user presses the start button attached to the reading apparatus main body. Then, inside the reading device, reading conditions such as resolution and gradation are set for pre-scanning (S3), and then reading of an image is started (S4). In this case, all the read image data is stored in the storage unit 23 inside the reading device (S5),
During this time, there is no communication with the host 26 and it is not occupied. After reading all the images, the communication with the host 26 is enabled, and when the prescan start command is received from the host 26 as in the conventional case, the image data stored in the storage unit 23 is input / output unit. It is sent via 24 (S10). That is, the host 26 is occupied only by the data transfer time, and the host 26 can be effectively used. When the instruction from the host 26 is not prescan, normal reading is performed.

In this way, the image reading apparatus of this embodiment can improve the efficiency of use of the host 26 during prescan, which is frequently used.

The present invention is not limited to prescanning,
If the data volume of the scanned image does not increase too much,
It can also be used for normal reading.

[0021]

As is clear from the above description,
According to the present invention, without using an external device during coarse reading,
Rough scanning is started by operating only the main body of the reading device, the image data is temporarily stored in the storage means inside the main body, and the data is sent to the outside to reduce the exposure time and the time required to move the reading sensor. The external device can be opened.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an overall configuration of an image reading apparatus.

FIG. 2 is a diagram illustrating a reading unit of the image reading apparatus.

FIG. 3 is a diagram illustrating a circuit configuration of an image reading device.

FIG. 4 is a flowchart illustrating an operation of the image reading apparatus.

[Explanation of symbols]

 10 control board 16 document 17 light source 20 CCD 23 storage unit 24 input / output unit 27 connector 28 start button

Claims (1)

[Claims] 1. An image reading device for reading and scanning an original image, comprising: coarse reading means for reading an image of the entire reading area at a low density; and instructing means for instructing the start of the rough reading without using an external device. A storage unit for storing the image data read by the rough reading, and a communication unit for transferring the image data in the storage unit to the outside when an instruction to start the rough reading is given from the outside. Characteristic image reading device.