JP3077341B2 - Document reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading apparatus for use in a facsimile apparatus and the like, and particularly to a document reading apparatus with improved reading accuracy.

[0002]

2. Description of the Related Art Generally, in a document reading apparatus of a facsimile apparatus, a standard mode (normal mode) and
The fine mode (fine mode) is selected. Normally, in the standard mode, reading is performed at a pitch of 3.85 lines / mm in the sub-scanning direction, and in the fine mode, reading is performed at a pitch of 7.7 lines / mm. Therefore, when the standard mode is selected, the reading pitch becomes coarser than in the fine mode. For this reason, when the standard mode is selected, the amount of unreadable image information increases, and when read data is output on paper, it is inevitable that the image resolution is reduced. For example, by reading continuous vertical ruled lines,
When it was output on paper, the vertical ruled lines, which should have been continuous, were sometimes discontinuously cut off.

[0003]

In order to solve this problem, conventionally, an output value of read data of image information within a certain range is averaged, and the average value is set as image information of an area where reading is not performed. Was to be done.

However, this average value is calculated based on the assumption that image information corresponding to the average value exists, and it is necessary to determine whether or not the image information actually exists. Absent. For this reason, the output image may be different from the actual image information. In addition, complicated software processing and memory are required to calculate the above average value.

An object of the present invention is to provide a document reading apparatus capable of obtaining a high image resolution without requiring complicated software processing and memory.

[0006]

To achieve the above object, according to the Invention The document reading apparatus of the present invention, the main scanning direction for one line
Lights up the document for less than the scanning time.
A light source for irradiating a reading means for outputting image information data image information read in the main scanning direction and the sub scanning direction on the document, extending in the sub-scanning direction, and the read output data of adjacent two lines in an adding means for adding a setting unit for setting by converting the added data as a line of data, fine pitch the document in a sub-scanning direction
As well as the light source in the standard mode.
The gist of the present invention is to provide control means for intermittent lighting .

[0007]

According to the above arrangement, when the standard mode is selected , the original is fine-pitched in the sub-scanning direction.
And the light source is turned on intermittently.
You. For this reason, the image information on the original is read at the same line density as in the fine mode, the data for two lines is added by the adding means to obtain data for one line, and the added data is converted and set by the setting means. .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a circuit configuration of a facsimile apparatus to which the present invention is applied. A CPU (Central Processing Unit) 1 controls the operation of the entire facsimile machine based on a program stored in a ROM (Read Only Memory) 2. RAM (random access memory) 3
Stores various data such as facsimile numbers. NC
A U (network control unit) 4 controls a connection with a telephone line, and a diamond pulse (or DTM) corresponding to a facsimile number input by a numeric key.
F), and a function of detecting an incoming call.
A modem (modulator / demodulator) 5 modulates and demodulates transmission / reception data.

The key input unit 6 is provided with a plurality of numeric keys for inputting a FAX number, an image quality selection key for selecting an image quality of a read image of a document, and the like.
That is, in this facsimile apparatus, a standard mode and a fine mode are prepared as image quality modes for reading an original, and the reading device is switched to a desired image quality mode by operating an image quality mode selection key.

The feed motor 7 is used to feed the document in the sub-scanning direction. In this embodiment, the feed pitch is set so as to always be a fine pitch in the fine mode (7.7 lines / mm). I have. The feed motor 7 is connected to the CPU 1 via a driver 8, and the driver 8
The feed motor 7 is driven based on a command signal from U1. An LED (light emitting diode) 9 is provided as a reading light source, and irradiates a document with light. The LED 9 is connected to the CPU 1 via a driver 10, and the driver 10
Turn on ED9. The lighting time of the LED 9 is switched in accordance with the image quality mode selection by the image quality selection key,
As shown in FIG. 2, the light is always turned on in the fine mode, but is turned on intermittently based on the count of the timer 11 in the standard mode, and is half the time for scanning one line in the main scanning direction. Lights only for the time. That is, in the standard mode, the lighting time of the LED 9 is １ ／ of that in the fine mode.

C as a means for reading image information on a document
The CD (solid-state imaging device) 12 accumulates electric charge in proportion to the amount of incident light, and outputs the electric charge as image information data.
9 is reflected by the original, and the amount of charge stored by the reflected light is stored in RAM as image data.
3 in a predetermined area. Therefore, as described above, in the standard mode, since the lighting time of the LED 9 is の of that in the fine mode, the charge accumulation amount is also １ ／ (see FIG. 2). The printer 13 includes an ink jet printer or the like, and prints image information on printing paper.

The adding means is constituted by the CPU 1 and the ROM 2. Then, read output data extending in the sub-scanning direction and for two adjacent lines is added. The setting means comprises a CPU 1 and a RAM 3;
The added data for the line is converted as data for one line and set and stored in a predetermined area of the RAM 3. C
The PU 1 reads out the stored data and causes the NCU 4 and the modem 5 constituting the transmitting means to transmit the data.

Next, the operation of the facsimile apparatus configured as described above will be described. By the way, at the time of transmission of this facsimile machine, the ROM 2 is controlled under the control of the CPU 1.
The operation shown in the flowchart of FIG. The control means includes a CPU 1, a ROM 2,
And a RAM 3. That is, a predetermined reading image quality mode is selected by the image quality selection key (step S1). When the fine mode is selected, the original is sent at a fine pitch while the LED 9 remains lit, and the image information on the original is sequentially read line by line by the CCD 12, and the image information data is read. It is set as it is in the RAM 3 constituting the setting means (step S2). Thereafter, it is determined whether the reading operation is completed based on the EOP signal or the like (Step S).
7) If not finished, return to step 1 and repeat the above routine until the reading operation is completed.

On the other hand, when the standard mode is selected by the image quality selection key, the lighting time of the LED 9 is set to 1/2 of the fine mode (step S3), and the lighting timing of the LED 9 is controlled by the timer 11. . Next, the original is sent at a fine pitch (step S4), and the image information is sequentially read line by line by the CCD 12. This reading operation is repeated twice, and when the image information data of two adjacent lines is read (step S5), the data of the two lines are added and the data is added to the RAM 3 as data of one line.
Is stored (step S6). Thereafter, the data thus set is transmitted.

Therefore, in the case of the standard mode, unlike the conventional mode, the data of the image information existing between the lines in the normal mode (3.85 lines / mm) can be reflected on the transmission data without leaking. A high image resolution close to the mode can be obtained. In addition, the read image information data is added to data of two adjacent lines and set and stored in the RAM 3 as data of one line.
There is no need to increase the capacity of M3. Moreover, since it is not necessary to take an average value of a certain area in order to obtain a high image resolution, complicated software processing and a memory for the processing are not required. The present invention can be applied to a case where the facsimile apparatus is used as a copy and a case where the reading is performed in the standard mode and the recording is performed in the fine mode.

[0016]

[0017]

[0018]

As described above, according to the present invention, even when the standard mode is selected, an excellent effect that a high image resolution can be obtained without using complicated software processing or the like is exhibited.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a circuit configuration in which a document reading apparatus according to the present invention is embodied in a facsimile apparatus.

FIG. 2 is a timing chart of LED lighting and the like.

FIG. 3 is a flowchart illustrating an operation of the facsimile apparatus when reading image information.

[Explanation of symbols]

1. CP forming the adding means, the setting means, and the control means
U, ROM constituting the adding means and the control means , 3 ...
RAM constituting the setting means and the control means , 4 ... NCU,
5: Modem 9: LED as light source 12: CCD constituting reading means

Claims (1)

(57) [Claims] 1. A light source for illuminating an original, which is turned on for a time shorter than a scanning time of one line in the main scanning direction, and an image obtained by reading image information on the original in the main scanning direction and the sub scanning direction. Reading means for outputting information data, adding means extending in the sub-scanning direction and adding the read output data for two adjacent lines, and converting the added data as data for one line for setting Setting means and sending the document at a fine pitch in the sub-scanning direction
In the case of standard mode, the light source is turned on intermittently
A document reading device comprising a control unit for performing the operation.