JPH02210967A - Recorder - Google Patents

Abstract

PURPOSE:To prevent a change in a recorded picture due to a temperature change by correcting a voltage data of a white level in response to a temperature of an image sensor. CONSTITUTION:A microcomputer unit 1 at picture read receives a detection signal from a temperature sensor 10, corrects the signal according to a temperature data of an image sensor reading a succeeding white level data, the result is fed to an analog reproduction circuit 4, from which a white level data corresponding to the detected temperature. Since a voltage data after the correction is compared with a picture voltage data at a comparator 5, the change in the characteristic due to a temperature change of the image sensor is solved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a recording device that reads and records images using an image scanner unit, and particularly to a recording device that corrects temperature changes in the image sensor. .

[Conventional technology]

In this type of recording device equipped with an image scanner unit, the white level voltage data output from the image sensor when a reference blank sheet of paper is read by the image scanner is stored in memory in advance, and then the actual image is read. The image voltage data outputted at this time is compared with the self-level voltage data to record the image. At this time, the white level voltage data can be used permanently if a blank page is read and stored.

(Problems to be Solved by the Invention) Conventional recording devices are configured as described above, and the white level voltage data to be compared with the actual image voltage is fixed, so characteristics change due to temperature changes of the image sensor. However, there was a problem in that the recorded image changed due to temperature changes.

The present invention has been made with attention to such problems, and an object of the present invention is to provide a recording apparatus that prevents changes in recorded images due to temperature changes.

(Means for Solving the Problems) A recording device of the present invention includes an image scanner unit having an image sensor, and a white level voltage data output from the image sensor when the image scanner unit reads a reference blank sheet. Equipped with memory to store
In a recording device that records the image by comparing image voltage data output when an actual image is read by an image scanner unit with the white level voltage data, the white level voltage data is determined according to the temperature of the image sensor. This is provided with a correction means for correcting.

(Function) In the recording device of the present invention, the white level voltage data is changed by the correction means according to the temperature of the image sensor,
The image read by the image scanner remains constant despite temperature changes.

[Embodiment] Fig. 1 is a block diagram showing the circuit configuration of a recording apparatus according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a microcomputer unit that controls the entire system, and constitutes a correction means for correcting white level voltage data in accordance with the temperature of an image sensor, which will be described later. 2 is an image scanner unit having an image sensor such as a CCD line sensor, and 3 is the image scanner unit 2 which is provided in advance in the apparatus or is set at the reading position when reading a reference blank sheet from the image sensor. A serial interface RAM (memory) that stores white level voltage data to be output; 4 is an analog reproduction circuit that reproduces the white level voltage data stored in the serial interface RAM 3; 5 is a white voltage data that is output from the analog reproduction circuit 4; This is a comparator that compares the level voltage data with the image voltage data output from the image sensor when an actual image is read by the image scanner unit 2, and the output of the comparison result is input to the microcomputer unit 1.

6 is an analog-to-digital (A/D) converter that converts the white level voltage output when a blank sheet is read by the image scanner unit 2 into a digital value; 7 is a flip-flop that can handle digital values input in parallel; 8
is a switching circuit, and the above-mentioned white level voltage data is input to the serial interface RAM 3 for one scan via the comparator 6, flip-flop 7, and switching circuit 8. 9 is a control logic circuit for controlling data input/output in the above configuration, IO is a temperature sensor for detecting the temperature of the image sensor, and 11 is a connector for connecting to a host device not shown in the drawing.

Note that %Ll is an address line for controlling the serial interface RAM3, L2 to Ll11 are input/output lines, control lines, or signal lines of each part, and Vt in the figure is an image voltage depending on the brightness of the image read out from the image sensor. , Vw indicates the white level output from the analog reproduction circuit 4, address signals output from the SA&T microcomputer unit 1, S indicates various acknowledge signals from the control logic circuit 9 to the microcomputer unit 1, and 82 to Ss indicate the white level output from the analog reproduction circuit 4. Input/output signals or control signals of each part are shown.

Next, the operation will be explained.

In the recording device configured as described above, the digital data indicating the white level voltage stored in the serial interface RAM 3 is reproduced and outputted as an analog signal from the analog reproduction circuit 4, and this output voltage and the actual image read are output from the analog reproduction circuit 4. The comparator 5 compares the image voltage output from the image sensor at the same time, and the image is recorded based on the comparison result. That is, first, white level voltage data is created by the microcomputer unit 1 and stored in the serial interface RAM 3. At this time, a control signal S6 is output to the microcomputer unit 1 and image scanner unit 2 to cause the image scanner to read a blank sheet for creating white level voltage data. After the image voltage Vl output from the image sensor is compared with a reference value by a comparator 6 and converted into a digital voltage, it is inputted to a flip-flop 7 through an output line L2, where it is latched by a signal from an l1al logic circuit 9. do. At this time, the control logic circuit 9
The switching circuit 8 selects the output line L3 of the flip-flop 7 according to the control signal s2 from the flip-flop 70.
The voltage data latched by the knob 7 is input to the serial interface RAM 3 from the input line L via the switching circuit 8. Then, a predetermined address is added to the address line L from the control logic circuit 9, and white level voltage data for one scan of the image sensor is written into the serial interface RAM 3. And this RAM3
As described above, the data written in is reproduced by the analog reproduction circuit 4 and compared with the image voltage data, but in this embodiment, as described above, the white level voltage data correction means is performed by the microcomputer unit 1. The white level voltage data output from the analog reproduction circuit 4 is changed according to the temperature of the image sensor during actual image reading (recording).

FIG. 2 is a flowchart showing the operation when reading the above-mentioned actual image. At the time of reading this image, when a paper (original) to be recorded is set in the image scanner unit 2, the microcomputer unit 1 detects that the paper has been set by the control signal ss (step S,), and at the same time the temperature sensor The temperature of the image sensor is read by manually inputting the detection signal from 10 through the signal line LI2 (step S2). Next, the control logic circuit 9
is controlled via the control line L, so that the output address signal SA and the address signal output from the control logic circuit 9 to the address line Ll match (
Step S3). Then, the addresses are sequentially changed and the white level voltage data stored in the RAM 3 is read from the terminal 5fN1 through the output line L7 (step S4). Next, the read white level voltage data is corrected according to the image sensor temperature data read earlier, and white level voltage data corresponding to the temperature at that time is created by an internal arithmetic circuit (step Ss). The circuit 8 selects the output line L6 of the microcomputer unit 1, and inputs the white level voltage data created above from #14- of 5OUTI into the serial interface RAM 3 through the manual line L6. At this time, the address signal SA is sequentially changed, and the corrected (changed) white level voltage data is stored in an area different from the address area in RAM 3 that contains the white level voltage data before the change ( Step S8).

Next, the image scanner unit 2 is controlled by the control signal S5.
and starts feeding the set paper to the reading position (step s7). At the same time, the control logic circuit 9 is controlled to output the address generated by the internal address generator and the above-mentioned corrected self-level voltage data to the line L7 (step S8). At this time, the image sensor outputs the fed paper An image voltage vI is generated according to the image.

Further, the white level voltage data output to the output line LA of the RAM 3, that is, the correction data, is sent to the analog reproduction circuit 4 (step s9).
Meanwhile, white level voltage data corresponding to the detected temperature is output. Then, this corrected voltage data (actually partial voltage data) is compared with the above-mentioned image voltage data in the comparator 5, and as a result, the read image data (digital data) is read as the output signal s4 of the comparator 5. One line of image data is read by inputting the serial interface clock from the control logic circuit 9 to SCL from the 0 terminal (step S+o) - and this data is sent to the image scanner. Connect the signal line Lll to the host device connected to
This operation is repeated until the image of the autumnal equinox is read (step 512), and the recording of the image is completed.

In this way, the microcomputer rewrites the white level voltage data according to the temperature of the image sensor, outputs it from the analog reproduction circuit 4, and compares it with the actual image voltage data. It can respond to changes in characteristics and prevent changes in recorded images due to temperature changes.

In this embodiment, the reference value for binarizing the image signal is corrected according to the temperature, but the invention is not limited to this. For example, the amplification factor of the output of the image sensor may be corrected, or the image signal Correction may be performed by digital calculation.

〔Effect of the invention〕

As described above, according to the present invention, since the white level voltage data is corrected according to the temperature of the image sensor, it is possible to cope with changes in characteristics due to temperature changes of the image sensor, and to record data due to temperature changes. This has the effect of preventing changes in the image.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the circuit configuration of a recording apparatus according to an embodiment of the present invention, and FIG. 2 is a flow chart showing the operation of the circuit shown in FIG. 1.-1 Microcomputer unit (correction means) 2--Image scanner unit 3--Serial interface RAM (memory) 4-
- Analog reproduction circuit 5 - Comparator 8 - Total switching circuit 9 - Control ROSIC circuit 10 - Temperature sensor

Claims (1)

[Claims] an image scanner unit having an image sensor;
This image scanner unit is equipped with a memory that stores the white level voltage data output from the image sensor when reading a reference blank sheet of paper, and the image voltage data output when the image scanner unit reads an actual image is stored in the white level. A recording apparatus that records the image by comparing it with level voltage data, further comprising a correction means that corrects the white level voltage data in accordance with the temperature of the image sensor.